GitLab

Remove deprecated_default_sources_assignment_filter and replace
it with explicit is_win, is_mac, etc. sections.

Bug: 1018739
Change-Id: I9a5412ea3b92fd3322bb26b062b829a457dba7c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2443249Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813139}